In the face of the increasing demand for a variety of high speed digital data communication services (such as, but not limited to HDSL, ADSL and SDSL), telecommunication service providers are continually seeking ways to optimize utilization of their very substantial existing copper plant, that was originally installed for the purpose of carrying nothing more than conventional analog (plain old telephone service or POTS) signals. When providing a high speed digital line service to a subscriber site in response to a request by a competitive local exchange carrier (CLEC), such as an internet service provider (ISP), the incumbent local exchange carrier (ILEC), such as a Bell operating company (RBOC), will customarily dispatch a technician to a remote site serving the customer premises equipment.
At the remote location, such as a curbside junction box serving the customer premises, the ILEC technician will make a physical connection for the wireline pair, through which digital data service supplied by the CLEC is to be provided to the customer's data terminal equipment, in accordance with an installation ticket derived from an archival database kept by the telco. At that point, as far as the ILEC is concerned, the job is done, since the installer is unable to verify the connection.
This inability to verify the connection is due to the fact that, unlike a conventional POTS line, which is connected legacy analog equipment at the central office, and therefore provides dial tone that enables the craftsperson to make a call back to the central office (CO) and verify that the connection is correct, the digital wireline is not so terminated, making it a `silent` line. This silent condition of the digital line, coupled with the fact that the accuracy of the telco's records associated with any particular wireline pair are uncertain, frequently results in `no service` complaints from the customer and the need for follow up investigation by ILEC and/or CLEC service personnel.